Next time you plunk down some change on the table before leaving a restaurant, think about what might be behind that service with a smile. A new study warns that when Americans eat out, they feed into an industry fueled by exploitation and rampant discrimination against women.

The report, published by the labor advocacy group Restaurant Opportunities Center United (ROC) in partnership with a coalition of labor and women’s rights groups, details the restaurant industry’s secret recipe for fattening profits: low wages, harsh working conditions, erratic hours and multiple racial and gender barriers to job advancement.

In a testimony in the report, Claudia Muñoz recalled how her job at a national pancake chain restaurant in Texas demanded round-the-clock hours without overtime pay. Scrounging for tips, she earned as little as $160 per week. Muñoz says:

I had to eat less than $6.50 for the employee meal. … I could only afford pancakes. If you were on the schedule for only 5 hours, you couldn’t get a meal. There were days when I wouldn’t eat all day.

Surrounding her was a cross-section of the country’s forgotten workforce:

There were a lot of older people—women in their 50’s. They had children, families, some were single mothers … and $2.13 plus tips was all they had. … It really opened my eyes. It was Latinos cooking, white women working graveyard shifts, men working during the day. I saw the racism, sexism, and low wages in the industry. Everything I remember from that place was horrible.

It’s no secret that typical restaurant work is stressful and poorly paid, but it’s easy to dismiss as a side gig or a way-station on the road to more stable work. However, in today’s sour economy, as Muñoz witnessed, tough jobs in eating establishments are often the only way for struggling workers and their families to scrape by.

Wages are low for all restaurant workers: About four in ten earn at or below the minimum wage. But women in the industry have it especially hard, according to the study. Women make about 79 cents to every dollar earned by men. While this is approximately the national gender wage gap, but the ROC report points out a key distinction when it comes to the restaurant industry: “In many sectors, lower wages for women are often a product of discriminatory employer practices, but in the restaurant industry, lower wages for women are also set by law.”

Federal law makes the labor of tipped workers especially cheap (assuming that tips will make up the difference): a subminimum wage of just $2.13 compared to the standard $7.25 for other sectors. And of restaurant workers who rely on tips, most are women, concentrated in jobs like serving and tending the counter.

The lower-wage tier for restaurant work reflects a legacy of discrimination in labor regulation. Historically, sectors relying heavily on women and people of color, such as domestic work and farm work, have been excluded from critical labor protections.

But the inequity restaurant workers face isn’t just a bread-and-butter issue of wages. A national survey of several thousand restaurant workers found that:

90 percent lack paid sick days and 90 percent do not receive health insurance through their employers. One third of all female restaurant workers … lack any kind of health care, whether provided by their employer or otherwise.

Families suffer when parents can’t afford to take a day off to care for an ill child. And when sick food-service employees drag themselves to work, everyone is at risk. A majority of restaurant workers reported “going to work and cooking, preparing, or serving food while sick,” according to ROC’s study–a startling 70 percent among women. Imagine a bout of the flu in a hot, crowded kitchen, and how many hands touched your salad on its way to the table.

While they’re needlessly exposed to health risks, women are also acutely vulnerable to being sexually violated at work. According to ROC’s national survey of about 4,300 restaurant workers, some ten percent “reported that they or a co-worker had experienced sexual harassment in their restaurant.” The climate of abuse, the report found, is aggravated by employers’ failure to provide adequate workplace trainings or enforce formal rules against harassment.

ROC’s research reveals that the day-to-day hardships and indignities of restaurant work are compounded by long-term structural barriers of gender and racial segregation, which keep many women in marginal, irregular jobs with little hope of moving up from, say, server to manager.

So what can be done to fix the restaurant industry? Some states have already set higher wage floors for restaurant work. If the federal government were to do so, raising the national subminimum wage to $5.08, it would immediately boost the pay of an estimated 837,000 workers, most of them women, according to ROC. And that would simultaneously shrink the gender wage gap in the industry by one-fifth.

For now, just as most of Claudia’s customers probably barely noticed the exhausted workers bustling around them, the abuses throughout the restaurant industry appear to be invisible to the political establishment.